The Net-Zero Imperative

OXFORD – The world has reached an historic agreement on climate change. The deal concluded at the United Nations Climate Change Conference in Paris commits countries to take steps to limit warming to “well below” 2º Celsius relative to pre-industrial levels and to pursue “efforts” to limit warming to 1.5ºC. It also obliges developed countries to provide $100 billion per year in assistance to developing countries. But, unfortunately, the final negotiations dropped the one number that truly matters for the future of our planet: zero.

That is the net amount of carbon dioxide we can emit if we are ever to stabilize the planet’s temperature at any level. Zero, none, nada. The Earth’s atmosphere-ocean system is like a bathtub filling up with CO2 and other greenhouse gases: The higher the level, the warmer the planet will be.

The emissions tap must be turned off once the bathtub reaches a level associated with a certain level of warming – say, 2ºC, above which, scientists nearly unanimously agree, the risks become severe, tipping points become possible, and civilization’s ability to adapt is not guaranteed. Otherwise, the atmospheric bathtub will keep being filled, warming the planet 3º, 4º, 5º, and so on, until emissions eventually stop – or we go extinct. The sooner we turn off the tap, the lower the temperature at which the climate stabilizes, the less risk we will face, and the lower the cost we will incur in adapting to a warmer planet.

Only about half the CO2 we dump into the atmosphere stays there – the rest is quickly redistributed into the oceans and biosphere. But, as the oceans become increasingly saturated and able to absorb less, the amount that is redistributed is declining. Likewise, warming temperatures cause soils to release more CO2, causing yet more warming.

The only way to get CO2 out of the bathtub once it’s there is, almost literally, to bail it out. There are natural processes that “re-fossilize” CO2, but they are far too slow to matter.

Carbon capture and storage (CCS) technology takes CO2 out of emissions from coal- and gas-powered generating plants and sequesters it underground. While this does not do anything about the existing CO2 in the bathtub, CCS is technically capable of reducing emissions from coal and gas close to zero. But it remains very expensive, and efforts to develop the technology at scale have moved slowly.

From large-scale CCS, it is only a small step to take existing CO2 from the air and sequester it. But “CO2 disposal” technologies are still at a relatively early stage of development. If we continue on our current path, the scale on which they would have to operate would be formidable.

So we are in a race. Can we turn the tap to zero net emissions before the tub hits a level that takes us above the 2ºC threshold set in Paris? In fact, even that level may not be low enough. As the Paris agreement recognizes, many scientists believe that warming above 1.5ºC is risky and that adaptation to it will be extremely expensive, particularly for developing countries and island states.

The good news is that if we somehow stopped all emissions today, temperatures would continue to rise only for a decade or so, before stabilizing. But with the emissions tap still on high, we are rapidly running out of room in the tub. We can emit less than half of our historical CO2 emissions to date before we probably exceed the 2ºC threshold. On our current course, we will reach that point by 2040-2050.

This is why most scientists and a growing number of business leaders and investors are calling for a clear goal that emissions must go to net-zero before warming reaches 2ºC. In May 2015, the International Chamber of Commerce and CEOs from around the world called for a zero emissions goal. In Paris, leading investors and Bank of England Governor Mark Carney, along with Bloomberg CEO Michael Bloomberg, also endorsed net-zero emissions, citing systemic risks to the financial system from climate change. It is a goal that sends an unambiguous signal that CO2-emitting industries will either have to change or die, and that the future lies with zero-emissions technologies and businesses.

While the net-zero objective was dropped by the negotiators in Paris, it should be endorsed by individual countries in their plans, reinforced by the G-20, and eventually enshrined in the UN agreement. For the planet, it is zero or bust.

Comments

FROM THE AUTHORS: In the piece we should have more clearly noted that Article 4.1 of the Paris Agreement commits countries to undertake rapid reductions “so as to achieve a balance between anthropogenic emissions by sources and removals of sinks of greenhouse gases in the second half of the century”. As several readers have correctly pointed out, this is technically the same as net-zero, and it is very important that this language was included in this historic agreement, which we fully support. It is important to note that in the long term, natural sinks of CO2 are too slow and small to matter, so the only way of balancing residual CO2 emissions is by artificial CO2 removal, which as we point out is both hard and unproven. Thus the point of our piece is that many people, including many business leaders, investors, media, politicians, and even experts, don’t realize that meeting the Paris goal of 1.5-2 degrees means getting to zero emissions. “Balance of sources and sinks” is a bit technical for most people, but “zero” is a number everyone understands. Post-Paris this needs to be made clear - an economy based on dumping CO2 into the atmosphere has to end and the clean energy economy must begin, not in some distant future, but in the coming decades.- ERIC BEINHOCKER AND MYLES ALLEN Read more

The leaders put on a good show, a PR success, made to be seen as a great achievement in order to raise their failed profiles. Anticipated success rate for implementing the deal…...next to zero. Read more

Saying *zero* rather than net-zero clarifies things a bit - fossil fuel age is over and it's not coming back. The countries and companies which transform quickest will be the winners in this historic shift. "Negative emission" technologies are a chimera like nuclear fusion, as most people seem to realize. We're unable to store hazardous or nuclear waste and want to store CO2? Let's be realistic. Read more

Actually, very little has changed since one month ago. Why suddenly is this or that an "imperative" which was not an imperative 30 days ago? Until numerous laws change all over the world in a way that limits carbon production, or alters prices so that no one wants to produce carbon, very little has changed. Read more

I've heard it said that if people stopped emitting GHGs entirely, today, the earth (land, air, water) would continue warm for a time because the already-existant GHGs would continue to trap new heat, daily (just not as fast as if we continued adding to GHGs).

But the scientists also say -- unless I'm misled -- that a complete stop to emissions would immediatelt stop earth-warming, meaning (as I understand or misunderstand) thart the further warming over 1000 years would be a warming of the oceans.

The continuing (in any scenario) warming of oceans and continuing acidification of oceans as CO2 is absorbed by them cannot be a "good thing", so we should "get to Zero" ASAP and not slow up becuase things cost too much, or it's too inconvenient. after all, it's going to be inconvenient in any case. Read more

I've heard it said that if people stopped emitting GHGs entirely, today, the earth (land, air, water) would continue warm for a time because the already-existant GHGs would continue to trap new heat, daily (just not as fast as if we continued adding to GHGs).

But the scientists also say -- unless I'm misled -- that a complete stop to emissions would immediatelt stop earth-warming, meaning (as I understand or misunderstand) thart the further warming over 1000 years would be a warming of the oceans.

The continuing (in any scenario) warming of oceans and continuing acidification of oceans as CO2 is absorbed by them cannot be a "good thing", so we should "get to Zero" ASAP and not slow up becuase things cost too much, or it's too inconvenient. after all, it's going to be inconvenient in any case. Read more

These 'undertakings' at Paris may not make much difference. Carbon arbitrage will just move production to where there is poorer compliance, which will boost economic activity there, which will further incentivise further cheating. Read more

Acidification of our oceans is a problem also caused by CO2 emissions, one that we should also worry about. Enhanced weathering of olivine can help a bit on that front, as it attacks the problem by first neutralizing the acidity caused by CO2 dissolving in water on land and sea. By doing that, the dissolved CO2 is transformed from carbonic acid into bicarbonate, which is neither acid or basic, but helps to buffer the pH of soil and sea at the pH where it should be. And if we do that, the same soil and sea will be able to absorb more CO2 from the air more easily again. Probably not a panacea, but certainly an option that should be added to our toolbox of solutions. Look it up: enhanced weathering of olivine.

Alternatively, there is also the idea for a reactor in which the CO2 emissions can be made to react with a sludge of water and olivine powder. The resulting carbonate can then be used for building material. http://www.innovationconcepts.eu/CO2EnergyReactor.htm

Now we've at COP21 agreed that the goal is to stay below 2ºC or even 1.5ºC, those countries that can take the lead in technologies to decarbonize will have good chances to profit from that position. We're already seeing how wind and solar energy have become great growth industries. One issue is that current CO2 emissions trading/taxing schemes have not been designed to also support the deployment of methods to remove CO2. But that can be fixed. Read more

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